Speculations about the celebrity line-up of "Dancing With the Stars" season 21 are starting to pile up, but fans are still looking forward to the confirmed roster for the upcoming season. 

Several pro dancers were very vocal about their dream of seeing Caitlyn Jenner join the next lineup of competitors in ABC's long-running celebrity dance competition. Even five-time Mirror Ball trophy winner Derek Hough and fellow pro dancer Mark Ballas both said that they want to be partnered with the controversial celebrity, while former "DWTS" pro Cheryl Burke recently stated that Caitlyn will be a welcome addition to the show. 

"I think Caitlyn [Jenner] would be amazing on 'Dancing With the Stars,'" Burke told Entertainment Tonight. "The whole family has basically done it. I danced with Rob [Kardashian]. Kim [Kardashian] did it." 

Burke was paired with Jenner's stepson Rob in "DWTS" season 13 and they ended in the second spot. On the other hand, Rob's older sister Kim joined the show in season 7 wherein she and Ballas became the third pair to be eliminated. 

However, a source told Hollywood Life that the "DWTS" execs are having a hard time getting the current Vanity Fair cover model onboard the show.

"DWTS is losing hope on getting Caitlyn for the show," the source reportedly said. "The offer was made, but scheduling, money and a few other bumps in the road are making producers feel that they should give up on their chase."

However, Jenner's rep told the publication that they never received any offer from ABC.  

If the 65-year-old former Olympic gold medalist will not join the show's 21st season, other rumored celebrities can take her place, including Latin superstar Ricky Martin, actresses Heather Locklear and Marilu Henner, supermodel Christie Brinkley, "Glee" star Chris Colfer, and singer Nick Lachey, whose brother and 98 Degrees band mate Drew won in season 2. Demi Moore is also rumored to join the competition after her daughter Rumer Willis won season 20's Mirror Ball Trophy.

ABC is expected to introduce the celebrity contestants for "Dancing With the Stars" season 21 in "Good Morning America" in late August. The season will premiere on Sept. 14.